Oxygenative and Dehydrogenative [3 + 3] Benzannulation Reactions of α,β-Unsaturated Aldehydes and γ-Phosphonyl Crotonates Mediated by Air: Regioselective Synthesis of 4-Hydroxybiaryl-2-carboxylates.

摘要: Regioselective synthesis of 4-hydroxybiphenyl-2-carboxylates via the base-mediated oxygenative [3 + 3] benzannulation reaction α,β-unsaturated aldehydes and γ-phosphonyl crotonates is reported. A hydroxyl group installed in final product on originally phosphorus-bound carbon a novel dehydrogenative transformation. The proceeds rapidly an open flask, uses atmospheric oxygen as oxidant, affords good yields substituted biaryl phenols.